Beverage forming and dispensing system

ABSTRACT

A beverage dispensing system includes separate valves for controlling the flow rate of a diluent and a concentrate. Various concentrates of different viscosities can be used and the selected concentrate is identified. The flow rate of the concentrate is determined based on temperature and pressure and on information related to the identified concentrate. The valves are controlled so that the concentrate and diluent reach target flow rates. The target flow rates satisfy a target ratio of diluent to concentrate. If the actual flow rates cannot reach the target flow rates, then the target flow rates are modified to satisfy the target ratio. The structure of the concentrate valve is designed to accommodate proportional metering of any one of the various concentrates.

This application is a divisional of and claims priority to and thebenefit of U.S. patent application Ser. No. 10/412,681, which was filedon Apr. 14, 2003 and which claimed priority to and the benefit of U.S.Provisional Patent Application Ser. No. 60/380,849, filed on May 17,2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to beverage forming and dispensingsystems. More particular, the present invention relates to beverageforming and dispensing systems for effectively preparing a beveragemixture from concentrate, and even more particularly to beverage formingand dispensing systems for effectively monitoring and controlling thequality of a post-mix product. The present invention further relates toa dispensing valve assembly of a single design that can be used with anyof various types of concentrates.

2. Description of the Related Art

Beverages formed from concentrate are enjoyed around the world. Animportant advantage of forming a beverage from a concentrate is thatonly the concentrate need be shipped to the dispensing site; anyavailable water supply at the site can be used to form the bulk of thefinal mixed product. A typical application of forming a beverage from aconcentrate is a post-mix beverage dispensing system, commonly referredto as a fountain system, that mixes a syrup concentrate with carbonatedwater to form a beverage.

Improving the quality of fountain beverages to meet the goal of a“bottle quality” carbonated beverage delivered by on-premise fountainequipment has been a long, ongoing process. Fountain equipment mustconsistently carbonate water to proper CO₂ volumes, cool product to thedesired serving temperature and dispense water and syrup at a preciseratio to deliver the consumer's drink with the desired quality. All thiscritical functionality must be delivered from a piece of equipment afraction of the size and cost of traditional bottle-plant equipment andwith none of the rigorous plant maintenance procedures performed on adaily basis. Nevertheless, this quality goal has driven many designinitiatives with varying degrees of success.

Standard beverage valves require manual adjustment of water-to-syrupratio and readjustment based on seasonal changes in temperature. In suchdispensers, trained technicians must adjust carbonators during summermonths when the water temperature is higher. After adjusting thecarbonator, the technician must then readjust the water-to-syrup ratioof each valve, which can take a significant amount of time and result insignificant cost. Although ideally such standard beverage valves areintended to maintain a correct water-to-syrup ratio once adjusted, inreality the ratio needs to be adjusted periodically to maintain a propertasting beverage. Further, such valves require periodic cleaning.

Other known devices provide means to regulate syrup flow only, but onlyfor a very limited set of operational conditions.

SUMMARY OF THE INVENTION

The present invention can provide a system for improving the quality ofa dispensed beverage from a carbonated beverage forming and dispensingsystem.

The present invention can also provide a system for controlling theconcentrate and water supplies in a beverage forming and dispensingsystem to control the quality of a dispensed beverage.

The present invention can still further provide a system that can changethe control of the brixing ratio to that corresponding to any one of anumber of concentrates.

In addition, the present invention can provide a system that candispense water and concentrate at a desired ratio throughout itslifetime without maintenance or adjustment.

Still further, the present invention can provide a system including anozzle assembly in which the internal components of the nozzle assemblycan be kept free of incursion of liquid.

These and other aspects, objects, and features of the present inventionwill become apparent from the following detailed description of thepreferred embodiments, read in conjunction with, and reference to, theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the control arrangement of the beveragedispensing system of the present invention.

FIG. 2 is a schematic view of the valve assembly according to oneembodiment of the present invention.

FIG. 3A is an idealized cross-sectional view of the valve assemblyaccording to the first embodiment of the present invention with theindividual valves in a closed state.

FIG. 3B shows the valve assembly of FIG. 3A with the valves in an openstate.

FIG. 4 is an exploded perspective view of the valve assembly accordingto the first embodiment of the present invention.

FIG. 5A is a cross-section of an elevational view of the lever actuatingsystem of the present invention.

FIG. 5B is a cross-sectional view taken along section line 5B—5B of FIG.5A.

FIGS. 6A–6C are sectional views of a flow control valve used in a valveassembly according to a second embodiment of the present invention.

FIG. 7 is an exploded perspective view of the valve assembly accordingto the second embodiment of the present invention.

FIG. 8 is a partial assembled perspective view of the valve assemblyaccording to the second embodiment of the present invention.

FIG. 9 is a functional diagram of the control algorithm according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 depicts a schematic diagram of the beverage forming anddispensing system 10 according to the present invention. System 10includes a valve assembly 20, a carbonated water supply 30, a syrup orconcentrate supply 40 and a power supply 50. Valve assembly 20 ismountable on a well-known base or tower (not shown), through which theconcentrate, carbonated water and power is supplied.

Valve assembly 20 includes a controller 22, such as a microprocessor,for controlling the flow rate of the carbonated water and concentrate ata predetermined ratio or brix. Microprocessor 22 is powered throughpower source 50, which can include transformers to provide a DC voltage.Carbonated water source 30 can include a well-known carbonator tank anda cold plate (unshown) to chill the water supply, if desired.Concentrate supply 40 can be in the form of a bag-in-box type and theconcentrate is typically pumped by a concentrate pump 41.

Valve assembly 20 includes two flow control units or devices 24, 26.Flow control device 24 controls the flow rate of the carbonated waterand flow control device 26 controls the flow rate of the concentrate.These flow control devices can be formed integrally or separately withinthe valve assembly. Each flow control device is in the form of asolenoid-operated valve that can be controlled by pulsewidth modulation(PWM) by microprocessor 22.

Referring to FIGS. 3A and 3B, the flow control devices will bedescribed. Each flow control device 24, 26 includes a valve inlet 241,261 and a valve outlet 242, 262, formed in a valve body. Valve inletsand outlets communicate through valve passages 243, 263, in which valveseats 244, 264 are formed. A restriction 259 of a predetermined orificesize is inserted in concentrate flow path 263. Conical poppets or valvemembers 245, 265 are formed complementarily to valve seats 244, 264 toselectively engage therewith to close and open the valve passages tovarying degrees. Valve shafts 246, 266 are connected to poppets 245, 265and act as a plunger or armature of a solenoid. Coils 248, 268 areenergized and de-energized by pulsewidth modulated signals frommicroprocessor 22 to control movement of the poppets. The valves arenormally closed by springs 247, 267, which bias poppets 245, 265 intoengagement with valve seats 244, 264. Energization of the solenoidsmoves the poppets away from the valve seats to open the valves.

Poppet 245 of water flow control unit 24 is of a single conical ortruncated conical shape. As poppet 245 is lifted by action of itssolenoid, the gap between the poppet and valve seat 244 increases. Theflow rate of water through flow passage 243 is substantiallyproportional to the distance the poppet is raised. Since the viscosityof carbonated water is substantially the same between its freezing andboiling points, the flow rate of water through regulator 24 can beaccurately controlled regardless of temperature.

On the other hand, poppet 265 of syrup flow control unit 26 is of ageometry that is more compound than that of water poppet 245. As shownin FIG. 3B, poppet 265 is formed of two conical or truncated conicalsections 265 a, 265 b. Section 265 a, which is closer to armature 266,is formed from a cone of larger dimensions than that of section 265 b.Section 265 a fits complementary within valve seat 264 and will shut offflow of concentrate through passage 263 when fully seated. The reasonfor the compound geometry of poppet 265 is to accommodate concentratesof a wide range of viscosities. For example, with syrups closer to theviscosity of water, a gap between section 265 a of poppet 265 and seat264 is used to control the flow rate, whereas concentrates of higherviscosities can be controlled with a gap between section 265 b of poppet265 and the valve seat. As with flow control unit 24, flow ofconcentrate through flow control unit 26 is substantially proportionalto the distance the relevant section 265 a or 265 b is moved.

Referring again to FIG. 1 and to FIG. 2, measurement of the flow ratesfor concentrate and water will be described. The outlets of flow controlunits 24, 26 are connected to outlet passages 25, 27, which converge ina nozzle 28. A flow sensor 32 is provided in water outlet passage 25.Sensor 32 is preferably in the form of a turbine flow meter, forexample. Water flowing through outlet 25 turns the turbine so that therotations of the turbine over time are proportional to the flow rate. Asensor utilizing the Hall effect can count the rotations of the turbineand send the count back to microprocessor 22. Alternatively, sensor 32can be positioned upstream of flow control unit 24 (as shown in FIG. 2).

Two sensors are provided in the syrup line. A syrup temperature sensor42 can be provided either upstream or downstream of flow control unit26. Temperature sensor 42 can be in the form of a thermistor andmeasures the temperature of the syrup. A pressure sensor 44, such as apressure transducer, is provided so as to detect the pressure of thesyrup between poppet 265 of flow controller 26 and restriction 259.Pressure sensor 44 measures the back pressure in the syrup created byrestriction 259. When the detected temperature and pressure of the syrupare fed back to microprocessor 22, the flow rate of the concentrate canbe readily determined.

Restriction 259 is placed in the syrup passage to create a significantpressure drop. Pressure drop values differ from one concentrate toanother because the viscosity of the various concentrates also differ.The temperature of the concentrate is measured because temperatureaffects viscosity. Program algorithms can be used to determine the flowrate for any syrup based on inputs of temperature and pressure.

The type of syrup or concentrate supplied to the system can beidentified a number of ways. For example, a microchip associated with aparticular syrup can be connected to controller 22 to provide theinformation necessary for controlling that particular concentrate.Alternatively, the information can be pre-stored in the controller andan operator can select which syrup is being supplied to the unit. Stillfurther, other means to identify the syrup can be used such as bar codeor magnetic strip reading and radio frequency identification. As shownin FIG. 1, a concentrate identification unit 60 is used to represent anyone of these modes of inputting the concentrate information.

The functions of controller 22 will now be described in more detail. Thecontrol algorithm of control software in controller 22 can be dividedinto three functional groups: background system functions, an innercontrol loop and an outer control loop. The background system functionsare basic functions needed to measure input data or generate outputsignals from the control software. These functions are generally simplerepetitive tasks that can be executed quickly. The background systemfunctions can include 1) analog sensor input conversion in which thesignals from the analog pressure and temperature sensors 42, 44 aredigitized, 2) digital count or timing input measurement in which thesignals from water flow sensor 32 are monitored, 3) sensor data noisefilter averaging to compensate for any noise inputs, 4) operatorinterface input state sensing to determine whether an operator hasactivated the system, 5) a logical input de-bounce filter function and6) timing for PWM outputs. At regularly scheduled intervals, each inputsensor value can be measured and a new filtered or average value updatedfor each sensor. At scheduled intervals, the operator interface inputsare sampled and the logical state is determined by a noise-filtering orde-bouncing process.

The inner control loop controls the water and concentrate flow controlunits 24, 26 during each dispensing cycle to provide respective flowrates with maximum response and stability. Controller 22 operates fromaveraged sensor data to control water and syrup flow rates to respectivetarget values or set-points. The inner control loop has predefinedprocess steps to analyze the determined actual flow rates and applycorrections needed to respective control PWM values. For example, if themeasured or actual flow rate is greater than a target flow rate, thenumber of or width of pulses supplied to a particular valve can beincreased to open the valve further and if the actual flow rate is lessthan the target flow rate, the number of pulses or width of the pulsescan be decreased. The pulse corrections take into account the rate ofchange of the sensor value toward or away from the target flow rate andmaximum change limits for correction allowed for any one updated cycle.The inner control loop can utilize either proportional feedback in whichsmall errors are corrected by small corrections and large errors arecorrected by large corrections, or differential feedback wherein therate of change of the signal is taken into consideration. By applyingpulses to the solenoids rather than a constant signal, the valve can becontrolled to maintain a desired opening, while saving energy andavoiding overheating.

The outer control loop ensures that the ratio or brix of the water andconcentrate is maintained. The outer control loop monitors the sameaverage sensor parameters as the inner control loop, but converts theaverage sensor data to water and syrup flow data for each sampleinterval and tracks performance over each total dispense cycle todetermine whether any changes are necessary in the inner control looptarget flow rates. That is, if the measured water flow rate cannot meetthe target water flow rate due to, for example, fluctuations in thepressure of the water supply, then the ratio of water to concentratecannot be maintained unless the concentrate flow rate is also changed.Therefore, if the water and/or concentrate flow rates cannot meet theset target flow rates, the target flow rates are modified so as to bewithin a controllable flow rate range, that is, a flow rate that can beattained yet still meet the predetermined ratio.

Each dispense cycle starts from an average water pulse count or syruppressure set point value established from memory defaults or the lastvalid dispense cycle. The current dispense ratio performance is resetwith the start of each dispense cycle. As ratio performance ismonitored, the outer control loop applies predetermined process steps toadjust the water or syrup target values to maintain the ratioperformance within allowable limits. If the ratio performance needscorrection, the outer control loop can take into account the rate ofchange of the ratio or relative positions of the water and syrup PWMcounts within their operating ranges to calculate and update to thewater and syrup inner loop target values.

Referring to FIG. 9, the control algorithm for the inner and outer loopswill be described. The valve control algorithm begins in the inner loopwith nominal syrup and water flow control target values or set-points.These can be derived from the concentrate identification information.The nominal flow rates are input to an outer loop bias value to createinner loop control targets or set-points SP_(s) or SP_(w). Calculatedflow rate feedback Q*_((s)), Q*_((w)) is compared to the set-points andan error value (error) is calculated. Each error value is used toincrease or decrease a flow control signal currently being applied toflow control unit 24, 26 so that the actual flow rate Q_((w)), Q_((s))is controlled to be equal to a respective set-point value SP_(w),SP_(s). The resulting change in the flow control unit output is measuredby respective sensors 32, 42, 44 and the sensor inputs are convertedinto updated feedback values. The updated values are used to adjust thePWM for a next inner loop cycle interval. The PWM cycle time isestablished by the highest update frequency for the flow control unitsand can range from 20–400 Hertz. If the PWM cycle time is taken to be 50Hertz, for example, each PWM cycle has a total time value of 20milliseconds. During each cycle, the flow control coil may be energizedfrom 0–100% of the cycle time and can be adjustable in step incrementsof 1% resulting in a time resolution of 200 microseconds. The amount ofadjustment to be applied is proportional to the calculated error andscaled to provide operational stability.

The outer loop monitors the performance of the inner loop flow ratefeedback signals during each inner loop cycle interval. Water and syrupflow rates are continuously compared during each dispensing cycle todetermine a present status of ratio accuracy for each dispensing cycle.When the calculated ratio accuracy for an individual dispense cycleexceeds an upper or lower acceptable control band value, a flow controlbias value is calculated and applied to the respective inner loop flowcontrol set points SP_(s), SP_(w) to keep the ratio accuracy withinspecification.

More particularly, at the end of each inner loop PWM cycle, thecalculated flow rate feedback signals Q*_((s)), Q*_((w)), are analyzedby the outer loop algorithm. The syrup flow rate is assigned a scaled,flow value FV_(s) and the water flow rate is assigned a scaled flowvalue FV_(w). FV_(w) is combined with FV_(s) in such a manner that adispense cycle ratio (DCR) value will be 0 if the water flow value isexactly 5 times greater than the syrup flow value (assuming a desired5:1 mixing ratio). The DCR value is initialized at 0 for each dispensecycle and at the end of each PWM output cycle, the DCR value willcontain the cumulative total of the individual cycles for the currentdispense cycle. An operational ±error band will be established for themagnitude of the DCR value before set-point bias adjustment is applied.If the cumulative DCR value remains within the operational band, no biasadjustment is made. When the DCR value exceeds the error band magnitudethreshold, a bias adjustment will be applied to the inner loop flow rateset-points until the DCR value is 0.

The outer loop algorithm determines which ±DCR band limit was crossedand the magnitude of the inner loop flow rate values operating when thatlimit was exceeded. If the DCR value limit indicates the ratio containsan excess of syrup and the syrup flow control module is currentlyoperating near its minimum flow value, then the water flow controlset-point SP_(w) is increased until the DCR value returns to 0. When theDCR value returns to 0, bias adjustment is ceased. Likewise, if the DCRvalue limit indicates the ratio has an excess of syrup and the waterflow is operating near maximum, then the syrup flow control set-point isdecreased. If there is an excess of water and a syrup flow is operatingnear its minimum, then the syrup flow control set-point is increased. Ifthere is an excess flow of water and the syrup flow is operating nearits maximum, then the water flow control set-point is decreased. Theamount of bias adjustment applied will be proportional to the error andscaled to provide operational stability.

The outer control loop also uses operator interface input data tocontrol overall functions of the valve assembly. The outer control loopcan also provide non-linear functions of the valve assembly, such assoft start/stop dispensing and syrup sold-out control. Soft start/stopdispensing can be defined as gradually increasing the PWM signals sentto the flow control units 24, 26 when dispensing starts and graduallydecreasing those signals when dispensing stops so as to avoid “waterhammer” effects. Syrup sold-out control can include monitoring thesignal from pressure sensor 44 and if a minimum syrup pressure is notdetected, then it is presumed the syrup supply is empty. The outercontrol loop should then control to cease dispensing of water andconcentrate until reset.

The physical structure of the valve assembly 20 according to the firstembodiment of the present invention is shown in more detail in FIG. 4.Valve assembly 20 includes a back mounting plate 302 that is mountableon a conventional beverage dispensing tower or fountain base 400. Plate302 includes inlet orifices 304, 306 for receiving concentrate andcarbonated water supplied from the fountain base, and mounting holes308, that engage with complementary mounting lugs on the base. A valvebody 310 includes corresponding inlet ports 312, 314 to connect with theinlet orifices of the back mounting plate 302. Valve body 310 alsoincludes the flow passages and valve seats described previously withreference to FIGS. 3A and 3B. The concentrate and water are received bythe valve body laterally and discharged vertically downward throughoutlets. Valve body 310 is connected at its underside to a diverterblock 330, which can receive a conventional diverter assembly 332 andcertain sensors, as will be described later. Valve poppets 245, 265 arereceived in the upperside of valve body 310 and move vertically asdescribed with respect to FIGS. 3A and 3B. The valve poppets and theircorresponding springs 247, 267 are contained within valve tubes 249,269, which guide their movement, and the valve tubes are received withincoil assembly 320, which houses the coils 248, 268.

Valve body 310 can include a recess 322 for receiving a thermistorcomprising the temperature sensor 42. In this embodiment, thetemperature sensor senses the temperature of the syrup upstream of thevalve. Diverter block 330 includes a port 332 in which restriction 259can be inserted in the syrup passage therein. Restriction 259 is held inplace by a plug 334. Upstream of the restriction port 332 in diverterblock 330 is a recess 336 for receiving pressure transducer 44 formeasuring the pressure of the syrup in the passage between the valve andthe restriction. Controller 22 can be in the form of an electronicprinted circuit board and can be positioned in front of the valve body310 and diverter block 330. Various 0-rings and connectors such asscrews and clips for assembling the components of the valve assembly areshown in the drawings, but not numbered.

The connected valve body 310 and diverter block 330 can be mounted on alower base plate 340. Base plate 340 can be mounted to back plate 302 byany suitable manner. The base plate includes a nozzle hole 342 as wellas a switch hole 344. A membrane 346 covers switch hole 344 in awater-tight manner. A membrane switch 345 for actuating the valveassembly can be positioned on base plate 340 above membrane 346.Pressure applied to membrane 346 can actuate the membrane switch. Alever 348 is mounted underneath base plate 340 and includes an actuationarm 350, which can be pressed by an operator, a fulcrum clip 352 and aswitch activating arm 354. Operation of lever 348 forces actuation arm354 to depress membrane 346 to activate membrane switch 345. Referringto FIGS. 5A and 5B, fulcrum clip 352 can be attached to a shaft 349provided on the tower 400 or on base plate 340. Spring arms 356 of lever348 contact spring clips 358 connected to base plate 340 to return thelever to its unactuated position. This design can be tolerant ofexcessive activation force by a user without damage to the switch.

A power supply cable 360 can supply power to the valve assembly. A cover370 can fit over the entire valve assembly and connect with base plate340. Although the valve assembly operates in a liquid environment, bothmembrane 346 and cover 370 can prevent a liquid from entering theinterior of the valve assembly.

An alternative to the flow control units described with respect to FIGS.3A and 3B will be described in respect to FIGS. 6A–6C. A typical flowcontrol module 500 to be used in place of flow control modules 24 and 26is shown in these figures. Flow control module 500 includes a housing502 that defines a flow passage of the water or concentrate. Valve seats506, 508 and 510 are provided in flow passage 504. A maximum flowrestriction orifice 515 is positioned in the flow passage between seats508 and 506. In addition, flow control disks 512 and 514 are alsoprovided in flow passage 504, with disk 512 seating on valve seat 506and disk 514 seating on valve seats 508 and 510. Disk 512 is of solidconstruction and disk 514 includes central restriction orifice 51 4a andouter through-holes 514 b. Each disk 512, 514 is movable between adownstream and an upstream position. In the figures, the liquid flow isfrom left to right, so the left position of each disk is the upstreamposition and the right position is the downstream position. The disksare caused to shuttle between the two positions by solenoids 516, 518.When no power is applied to the solenoids, the disks will assume thedownstream position, biased by the fluid flow. When the solenoids areenergized, the disks are moved leftward against the fluid flow to theupstream position.

Disk 512 is used to open and close the valve. In the position of FIG.6A, the valve is closed and in FIGS. 6B and 6C the valve is open. Disk514 is used to control the flow rate through the valve. The flow ratelimits are set by the size of orifices 514 a and 515. Opening orifice514 a sets the minimum flow rate and opening orifice 515 sets themaximum flow rate. When solenoid 518 is not energized, disk 514 assumesthe downstream position and all openings 514 a and 514 b are open toallow the maximum flow rate, as shown in FIG. 6B. To achieve the minimumflow rate, solenoid 518 is energized to force disk 514 against the flowof the liquid and seal openings 514 b against valve seat 510 so thatonly restrictive orifice 514 a allows flow. The sum of the areas of theholes 514 b in disk 514 is greater than the area of opening 515. As aresult, only a small change in pressure is required to move disk 514from the downstream position (maximum flow rate) to the upstreamposition (minimum flow rate).

In order to achieve a flow rate between the maximum and the minimum,power to solenoid 518 is pulse-width modulated to achieve the desiredaverage flow rate. The design configuration for solenoid 518 does notrequire a high voltage to move disk 514 to the upstream position. Theamount of travel distance and the mass of disks 512, 514 are designed tobe small to allow the valve to respond quickly to PWM changes toregulate the average flow rate. The range of orifice sizes for the waterflow control valve is 0.1–0.25 inches, while the range of orifices sizesfor the syrup flow control module is 0.020–0.110 inches. This linearflow-through design allows smooth flow without significant pressuredrop.

The physical structure of the valve assembly 20′ according to the secondembodiment differs somewhat from that of the first embodiment and isshown in more detail in FIG. 7. Valve assembly 20′ includes an inletmounting plate 602 that is mountable on a conventional beveragedispensing tower or fountain base (not shown). Plate 602 includes inletorifices 604, 606 for receiving concentrate and carbonated watersupplied from the fountain base, and mounting holes 608, 610 that engagewith complementary mounting lugs on the fountain base. A fluid inletbody 612 is connected to mounting plate 602. A fluid outlet body 614connects with fluid inlet body 612. Flow control regulators 500 (24, 26)can be sandwiched between fluid inlet body 612 and fluid outlet body 614to define separate water and concentrate flow passages. O-rings can bepositioned at every fluid junction to prevent leakage. Outlet passages25 and 27 are defined in fluid outlet body 614 similar to the elementsshown in FIG. 2. Water flow sensor 32 and concentrate pressure sensor 44can be mounted on outlet body 614 to measure the flow rate and pressureof the water and syrup flows, respectively. Syrup temperature sensor 42can be provided in the concentrate flow passage in fluid inlet body 612.Outlets of fluid outlet body 614 flow into nozzle 28. A diffuser 616 canbe positioned between fluid outlet body 614 and nozzle 28 to ensureadequate mixing of the concentrate and water. Restriction 259 can beplaced in line between diffuser 616 and the syrup outlet of fluid outletbody 614.

A conventional switch 618 for activating the valve assembly can bemounted on fluid inlet mounting plate 602 and activated by a lever 620,as is known in the art. Alternatively, the membrane switch of the firstembodiment can be used. Lever 620 is pivotally mounted on base plate 622which receives fluid outlet body 614. Controller 22, which can be in theform of an electronic circuit board, can be mounted on top of connectedinlet mounting plate 602, fluid inlet body 612 and fluid outlet body614.

The inner components of the valve assembly can be covered by rear valvecover 624 and front valve cover 626, which will be visible to theoperator. Syrup identification unit 60 can be mounted in front cover626. Front cover 626 can include indicia to visibly identify the type ofsyrup for a user and syrup identification unit 60 can provide electronicidentification of the concentrate to the controller 22. After mountingon the tower or base with mounting lugs inserted in recesses 610, aretaining clip 628 can be used to secure the valve assembly 20′ to thetower. Fluid inlet body 612 and fluid outlet body 614 can be connectedby screws or any other adequate means. The circuit board of controller22 can also be mounted by screws. Front and rear valve covers 624, 626can engage the base plate 622. A partial assembled view of valveassembly 20′ is shown in FIG. 8.

Although specific embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration. Various modifications of thedisclosed aspects of the preferred embodiments, in addition to thosedescribed above, may be made by those skilled in the art withoutdeparting from the spirit of the present invention defined in thefollowing claims, the scope of which is to be accorded the broadestinterpretation so as to encompass such modifications and equivalentstructures.

1. A dispensing apparatus for dispensing a beverage formed by mixing adiluent and a concentrate at a target ratio, said apparatus comprising:a diluent flow control valve formed of a first valve seat and a firstpoppet received within said first valve seat, said first poppet having asimple shape; and a concentrate flow control valve formed of a secondvalve seat and a second poppet, said second poppet having a morecompound shape than the shape of said first poppet.
 2. The apparatusaccording to claim 1 wherein said second poppet is formed of two or moresections of simple shapes serially connected.
 3. The apparatus accordingto claim 2 wherein said second valve seat is of a simple shape ofdimensions complementary to one of the two or more sections forming saidsecond poppet.
 4. The apparatus according to claim 3 wherein one of thetwo or more sections forming said second poppet is used in conjunctionwith said second valve seat to control the flow rate of a firstconcentrate and another of the sections is used to control the flow rateof a second concentrate having a different viscosity than that of thefirst concentrate.
 5. The apparatus according to claim 1 wherein saidfirst poppet has a simple conical shape and said second poppet is formedof at least two conical sections of different sizes and seriallyconnected.